1869. | CLASSIFICATION OF THE CARNIVORA. 11 
In the singular genus dilurus the auditory bulla is very small and 
simple, prominent and rounded on the inner side, with a very pro- 
longed bony floor to the external auditory meatus. The carotid canal 
is large and distinct, rather behind the middle of the inner edge of the 
bulla. Paroccipital process long and trigonal, standing backwards 
and outwards, quite unconnected with the bulla, curved inwards at 
the extremity in old animals. The condyloid foramen is distinct in 
a flat exposed surface between the paroccipital and condyle. There 
is a well-developed rounded mastoid process, quite distinct from the 
paroccipital. The glenoid foramen is large, situated between the 
inner end of the tympanic meatus and the most prominent part of 
the large postglenoid process. There is a distinct alisphenoid canal. 
To pass to the Mustelide :—Lutra is extremely Ursine in the base 
of its skull, although all the bones (including the auditory bulla) are 
remarkably thinned-out and flattened. The meatus is much pro- 
longed. The carotid foramen is placed rather nearer the anterior 
than the posterior part of the inner edge of the bulla. The glenoid 
foramen is very distinct. The cavity of the auditory bulla (as is the 
case with many of the Mustelide) is divided into several freely in- 
terecommunicating cells by thin incomplete bony septa placed trans- 
versely across the floor of the bulla, and connected at their outer 
end with the tympanic ring. The paroccipital process is greatly 
compressed from before backwards. The mastoids are prominent 
laterally. The foramen lacerum posticum very large. There is no 
alisphenoid canal. 
Enhydris differs from Lutra chiefly in the large size and more 
posterior position of the carotid foramen, and the yery small size of 
the glenoid foramen. 
Meles presents, in the most characteristic manner, the form of 
auditory bulla assigned by Mr. Turner to this group, “rising sud- 
denly on its inner side, and flattened off towards the meatus.” In- 
ternally it has two transverse imperfect septa rising from the floor. 
The meatus is considerably prolonged. The paroccipital and mastoid 
processes are very well developed and far apart, the former rather 
compressed and pointed, the latter tuberous. The carotid foramen 
is placed rather behind the middle of the bulla, The condyloid 
foramen is small, its hinder border partially overlapped by a slight 
ridge of bone passing from the paroccipital process to the condyle ; 
but it is quite superficial and distinct from the foramen lacerum pos- 
‘ticum. The glenoid foramen is distinct, though not very large. There 
is no alisphenoid canal. 
Taxidea differs from Meles in the remarkably inflated condition of 
the auditory bulla. Essentially, however, its characters are much 
the same; the bulla is not so dilated at its hinder part as to come into 
contact with the paroccipital process, though in front it reaches to 
such an extent as to overlap and obscure the glenoid foramen. It 
has several partial transverse septa. 
In Mephitis, on the other hand, this region of the skull is nearly 
as much expanded and flattened as in the Otters. The bulla forms a 
very small prominence. The paroccipital process is widely separated 
